Days after Minister Marmion came under fire for removing greenhouse gas conditions on Chevron's Wheatstone project, it has emerged the Department of State Development asked for similar concessions for the Browse LNG development.

The Government has defended the decisions by insisting the Federal Government's carbon tax had made State-based pollution controls redundant.

Documents obtained by Environs Kimberley under Freedom of Information laws show the DSD appealed against an Environmental Protection Authority report which recommended Browse have stringent pollution controls.

These included keeping emissions below a minimum level and having the performance of the companies involved independently assessed and publicised.

Despite the environmental watchdog's advice, which was subsequently backed by the independent appeals convenor, Mr Marmion scrapped the conditions in his eventual decision for the $40 billion project.

Instead, Mr Marmion said the Browse proponents, led by oil giant Woodside, should only have to report their greenhouse gas emissions annually.

Environs Kimberley director Martin Pritchard said the FOI documents suggested Mr Marmion had failed to stand up to a department controlled by the Premier.

"It shows how desperate the Premier is to make the Browse project happen at James Price Point," Mr Pritchard said. The Conservation Council of WA seized on the DSD's involvement to claim Mr Marmion had been derelict in his duties as Environment Minister.

Rejecting the accusations as disingenuous, Mr Marmion maintained the State had virtually no power to impose greenhouse gas limits because they had been overridden by Federal laws.

"(The EPA) recommended the project work to limit its emissions, however, the State does not have the power to place such limits and to put such conditions in place would duplicate the regulation of the Commonwealth," he said.

Mr Barnett denied removing the conditions on the basis they would simply duplicate the effects of the carbon tax amounted to an admission that pricing carbon would work.